Cementing multiple tubingless completions



Jan. 16, 1968 w. J. BIELSTEIN 3,3 3,688

CEMENTING MULTIPLE TUBINGLESS COMPLETIONS Filed April 19, 1966 SLURRY ,INVENTOR. WALTER J. BIELSTEIN,

m Wldz 6 5 United States Patent Office 3,363,688 CEMENTING MULTIPLE TUBINGLESS (IOMPLETIONS Walter J. Bielstein, Houston, Tex., assignor to Esso Production Research Company Filed Apr. 19, 1966, Ser. No. 543,692 10 Claims. (Cl. 166-21) The present invention concerns method and apparatus for cementing a plurality of pipe strings in well bores in so-called multiple tubingless completions.

Multiple tubingless completion refers to the current practice of running two or more small diameter pipe strings in a well without first lining the well bore with a large diameter casing pipe string. The small diameter casing pipe strings are run into the well separately or strapped together in a bundle and cemented in place by pumping a cement slurry down one of the pipe strings and out the lower end thereof into the space surrounding them within the well bore. It is important that the cement slurry completely fill the space surrounding these pipe strings and that a good cement bond between the pipe strings and the well bore wall is attained to seal otf formations traversed by the borehole, and to prevent channels from forming and migration of fluids from one hydrocarbon interval to another.

The present invention is an improved cementing technique to achieve more uniform placement of the cement surrounding the well pipes and to attain a better seal between the well pipe strings and the borehole Wall.

Briefly, the method of the invention includes the steps of separately running a rotatable drive pipe string and at least one other pipe string into a well bore; and rotating said pipe strings together in said well bore while simultaneously introducing cement into said well bore. When the cement has reached a desired level in said well bore, introduction of cement into the well bore is halted and thereafter rotation of the pipe strings is halted. The apparatus of the invention includes at least one subsurface drive-spacer means arranged on the drive pipe string and adapted to turn or rotate the subsurface portion of said other pipe strings in the Well bore and to maintain said pipe strings properly spaced during rotation thereof.

The invention will be more clearly understood from the following description taken with the drawings wherein:

FIG. 1 is a vertical View, partly in section, of apparatus arranged in position to conduct a cementing operation;

FIG. 2 is a view taken on lines 2-2 of FIG. 1;

FIG. 3 is a view similar to that of FIG. 2 showing apparatus arranged in a quadruple completion rather than the triple completion of FIG. 2;

FIG. 4 is a plan view of a triple completion illustrating modified drivespacer means;

FIG. 5 is an elevation view of the modified drive-spacer means of FIG. 4;

FIG. 6 is a vertical view of the drive-spacer means of FIGS. 1 and 2 modified by guide means positioned on the ends thereof;

FIG. 7 is a plan view of the apparatus shown in FIG. 6 in running-in position; and

FIG. 8 is a view similar to that of FIG. 7 showing the position of the guide means during cementing operations.

In FIG. 1 is shown a borehole 10 in which is cemented a surface casing 11. A wellhead 12 is connected to the upper end of casing 11 and a blowout preventer assembly 13 is flanged to the upper end of wellhead 12. A bell nipple 14 is flanged to the upper end of blowout preventer assembly 13. A plurality of pipe strings 15, 16 and 17 are suspended in Well bore 10 from a rotatable slip spider assembly 18 mounted on rotary 19 in a manner such that 3,363,688 Patented Jan. 16, 1968 when the slip spider assembly is rotated by means of rotary 19, the upper ends of the three pipe strings are rotated. Another arrangement in which the center pipe string 15 is rotated instead of the slip assembly 18 may be employed. In such an arrangement, rotation of pipe string 15 by means of the rotary would cause rotation of the slip assembly and pipe strings 16 and 17 supported therefrom.

The upper end of center pipe string 15 is connected to a swivel joint 20 to which is attached a pipe 21 leading to a source of cement slurry.

A drive-spacer bar 25 is welded to the lower end of pipe string 15. Bar 25 functions to space and rotate pipe strings 16 and 17. Additional drive-spacer bars, illustrated by bar 25' may be provided suitably spaced along the length of pipe string 15 to aid in spacing and rotating the subsurface portions of pipe strings 16 and 17. A scratcher assembly 35 may be arranged on pipe string 15 to scrape the Wall of well bore 10 and remove mud cake from the formation Wall to aid in bonding of the cement thereto. The lowermost end of pipe string 15 carries a conventional cement shoe 7 and pipe strings 16 and 17 are plugged on their lowermost ends as shown at 8 and 9, respectively.

Drive-spacer bar 25, as seen also in FIG. 2, includes a cylindrical collar 26 welded to pipe 15 from which two equally spaced-apart bar or plate members 27 radially extend.

In FIG. 3 a modified drive-spacer bar 25a is provided with a collar 26a from which three equally spaced-apart plate members 270 extend which separate and drive pipe strings 28, 29 and 30.

FIGS. 4 and 5 illustrate modified drive-spacer apparatus. Spacer plates 31 extend radially and are configured in the shape of one quarter of a cone and are equally spaced on pipe string 15b. Such configuration assures equal spacing of the pipe strings and is easily modified to accommodate the desired number of pipe strings to be used. For example, in a dual completion, a radially extending single one-half cone configuration would be employed.

Another modification of the drive-spacer bar is illustrated in FIGS. 6 and 7; a leaf spring guide 32 is mounted on a swivel 33 arranged on the ends of plate members 27c. The position of the leaf spring guides 32 when pipe string 15c is being run in borehole 10 is shown in FIGS. 6 and 7, and their position when pipe string 15c and plate members 27c are being rotated is shown in FIG. 8.

In the operation of the apparatus, drive-spacer bars 25, 25 are welded to pipe string 15, and, if desired, scratcher assembly 35 is also connected to pipe string 15. A suitable cementing shoe 7 is arranged on the lowermost end of pipe string 15 and pipe string 15 is run to a desired depth in well bore 10. Then, pipe strings 16 and 17 are run in well bore 10 to desired depths. When landed, the lower ends of pipe strings 16 and 17 are above the lowermost end of pipe string 15. Also, when landed, pipe strings 16 and 17 are at least 30 feet below the lowermost drive-spacer bar 25. Pipe strings 15, 16 and 17 are supported in well bore 10 by slips in a rotatable slip spider 18 mounted on the rotary 19. Swivel 2t and pipe 21 are then connected to pipe string 15. Slip spider 18 is rotated in rotary 19 which causes rotation of pipe strings 15, 16 and 17 in well bore 10. Cement slurry is then pumped through cementing pipe 21 and swivel 20, down pipe string 15 and out the lower end thereof into the well bore until the cement fills the annular space surrounding the pipe strings to a desired height. The pipe strings are rotated until the cement plug which follows the cement slurry hits casing shoe 7.

If desired, the direction of rotation may be reversed several times during the cementing operations.

a t.) During the running of the pipe strings, the pipe strings already run in the borehole may be supported by clamps installed below rotary table 19 and resting on bell nipple 14, or they may be suspended from racks attached to the rotary beam (not shown).

When drive-spacer bar 25 is formed of segments of a cone 31, as shown in FIGS. 4 and 5, equal spacing of the pipe strings 17 and 18 is assured. However, such equal spacing is not required since, regardless of string separation at their lower ends, the pipe strings could not wrap around one another.

In order to streamline driving of the pipe strings and to eliminate all possibilities of the pipe strings being rotated by drive-spacer bar 25 jumping bar 25 opposite a hole enlargement, a leaf spring guide 32 may be employed. As illustrated in FIGS. 6, 7 and 8, a swivel mounting 33 permits the leaf spring guide 32 to align itself in accordance with vertical and rotational movements of pipe string 15, thus providing a streamline feature while running pipe string and while rotating it.

Having fully described the method, apparatus, objects and operation of my invention, 1 claim:

1. A method of cementing multiple pipe strings in a Well bore comprising the steps of:

separately running a rotatable drive pipe string and at least one other pipe string into said Well bore; and

rotating said pipe strings together in said well bore while simultaneously introducing cement into said well bore.

2. A method as recited in claim 1 including the steps of:

halting introduction of cement into said well bore when said cement has reached a desired level in said Well bore; and

thereafter halting rotation of said pipe strings.

3. A method as recited in claim 2 in which said cement is introduced into the upper end of said drive pipe string and flows out the lower end of said drive pipe string into the space surrounding said pipe strings.

4. Apparatus for cementing multiple pipe strings in a well bore comprising:

a drive pipe string suspended in said well bore;

at least one other pipe string suspended in said Well bore and extending along side said drive pipe string; I at least one subsurface drive-spacer means arranged on said drive pipe string adapted to rotate said other pipe string in said Well bore when said drive pipe string is rotated; and

means at the surface adapted to rotate said drive pipe string.

5. Apparatus as recited in claim 4 including a drivespacer means arranged on the lower end of said drive pipe string.

6. Apparatus as recited in claim 5 in which said surface means adapted to rotate the upper end of said drive pipe string includes a rotatable slip spider adapted to rotate said drive pipe string.

7. Apparatus as recited in claim 6 in which the lower end of said other pipe string is closed and said drive pipe string is open-ended and including means connected to the upper end of said drive pipe string adapted to introduce cement into the upper end of said drive pipe string.

8. Apparatus as recited in claim 7 in which each drivespacer means comprises a cylindrical collar attached to said drive pipe string and provided with at least tWo spaced-apart radially extending bars.

9. Apparatus as recited in claim 8 including pipe guide means attached to the ends of said bars adapted to engage and guide rotation of said other pipe string upon rotation of said drive pipe string, said guide means being pivotally mounted on said bars in a manner so as to align said guide means with the direction of movement of said drive pipe string when running said drive pipe string in the borehole and to align with the direction of rotation of said drive pipe string when rotating said drive pipe string.

16. Apparatus as recited in claim 8 in which each drivespacer means includes a conically shaped portion thereof adapted to aid in spacing said other pipe strings about said drive pipe string.

References Cited UNITED STATES PATENTS 3,047,069 7/1962 Carter 16652 3,100,529 8/1963 McStravick et al 166-52 3,110,347 11/1963 Howard et a1 166-2l X 3,292,708 12/1966 Mundt 166241 3,302,714 2/1967 Bearden et al 16621 3,330,349 7/1967 OWsley et al. 166--21 OTHER REFERENCES Mills, 13.: Rotating While Cementing Proves Economical, The Oil Weekly, December 1939, pp. 14 and 15.

Buster, John L.'. Multiple Tubingless Completions (Parts 1 and 2), The Oil and Gas Journal, June 8, 1964, pp. 121-125 and June 15, 1964, pp. 89-91.

ERNEST R. PURSER, Primary Examiner.

D. H. BROWN, Assistant Examiner. 

